Effects of increased spacing on carbon mineralization rates and temperature in a stand of young balsam fir

1978 ◽  
Vol 8 (4) ◽  
pp. 398-406 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Inorganic Nitrogen ◽  
Carbon Mineralization ◽  
Basal Area ◽  
Balsam Fir ◽  
Litter Layer ◽  
Nitrogen Levels ◽  
Foliar N ◽  
Summer Temperatures ◽  
Mill Stand ◽  
Regular Spacing

Treatment to reduce density, from 19 000 stems/ha to about 1642 stems/ha at a regular spacing of 2.4 × 2.4 m, in a young balsam fir (Abiesbalsamea (L.) Mill.) stand stimulated carbon mineralization rates of the litter layer which were, in turn, positively correlated with inorganic nitrogen levels. Increased carbon mineralization rates were attributed to increased summer temperatures in the litter layer. Temperature measurements under the snow indicated a consistently lower winter temperature in the treated stand as compared with the control. The increased and more regular spacing in the treated stand resulted in more rapid basal area growth, increased needle weights, and greater foliar N concentrations, reflecting an increased nitrogen uptake by the trees.

One and two years impact of commercial thinning on spruce budworm feeding ecology and host tree foliage production and chemistry

1996 ◽  
Vol 72 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Éric Bauce
Keyword(s):  
Choristoneura Fumiferana ◽  
Soluble Sugars ◽  
Abies Balsamea ◽  
Basal Area ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
First Year ◽  
Commercial Thinning ◽  
Mill Stand ◽  
Second Year

Field rearing experiments of spruce budworm, Choristoneura fumiferana (Clem.), were conducted in conjunction with foliar chemical analyses, one and two years after a commercial thinning (removal of 25% stand basal area) in a 50-year-old balsam fir, Abies balsamea (L.) Mill., stand. The first year after thinning, spruce budworm larvae reared on the residual trees developed five days faster and removed 43% more foliage than those reared on control trees, but in the second year they developed two days faster and removed 37% more foliage. The increase in larval development rate was related to an increase in foliar soluble sugars while a reduction in foliar monoterpenes caused by the thinning apparently accounted for the greater amount of foliage ingested by the larvae. The first year after thinning, trees were more vulnerable to spruce budworm because there was no increase in foliage production and the trees were more heavily defoliated. However, in the second year trees were less vulnerable to the insect because there was an increase in foliage production that exceeded the increase in defoliation, hence a net gain in foliage. Results from this study showed that commercial thinning could reduce the vulnerability of balsam fir trees to spruce budworm if thinning is conducted two years prior to budworm outbreak, but the same silvicultural procedure could increase the vulnerability to the insect if it is conducted during an outbreak. Key words: spruce budworm, balsam fir, chemistry, thinning, defoliation

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

INORGANIC NITROGEN LEVELS AND NITRIFICATION POTENTIAL IN LOWBUSH BLUEBERRY SOILS

1988 ◽  
Vol 68 (1) ◽  
pp. 63-75 ◽  
Author(s):  
LEONARD J. EATON ◽  
DAVID G. PATRIQUIN
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulfate ◽  
Soil Nitrogen ◽  
Plant Uptake ◽  
Inorganic Nitrogen ◽  
Garden Soil ◽  
Laboratory Studies ◽  
Vaccinium Angustifolium ◽  
Nitrogen Levels ◽  
Lowbush Blueberry

Soil ammonium and nitrate in the top 15 cm of soil were monitored after application of ammonium nitrate and ammonium sulfate to plots at 14 PF (previously fertilized) and 12 NF (never fertilized) lowbush blueberry (Vaccinium angustifolium Ait.) stands representing a range of soil types and management histories. Overall, nitrate values in unfertilized and ammonium sulfate plots were higher at PF than at NF sites, suggesting greater nitrification at PF sites. In laboratory incubation studies, nitrification proceeded immediately in soil from a PF site, but only after a 4-wk lag in that from an adjacent NF site. Nitrification rates were low compared to that in a garden soil (pH 6.6). N-Serve inhibited nitrification in both soils. In ammonium nitrate plots, "excess" N values (N values in fertilized plots minus values in unfertilized plots) were higher for PF than for NF sites, suggesting greater immobilization, plant uptake or loss of N at NF sites. There was no evidence, in laboratory studies, of immobilization of added N by soil from either type of site. Rhizome N concentration increased significantly in response to fertilization at an NF site, but not at a PF site. Key words: Blueberry (lowbush), fertilizer and soil nitrogen

Attributes of forest strips used by snowshoe hare in winter within clear-cut boreal landscapes

2005 ◽  
Vol 35 (10) ◽  
pp. 2521-2527 ◽  
Author(s):  
François Potvin ◽  
Normand Bertrand ◽  
Jean Ferron
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Snowshoe Hare ◽  
Forest Patches ◽  
Clear Cut ◽  
Important Prey ◽  
South Central ◽  
Snowshoe Hares ◽  
Riparian Strips

The snowshoe hare (Lepus americanus Erxleben) is an important prey for many predators in the boreal forest. In this biome, clear-cut landscapes are generally large and consist of aggregated cutting blocks separated by narrow forest strips (typically 60–100 m wide). To identify attributes of forest strips that are important for snowshoe hares, we measured the use of strips using track counts over two winters in six clear-cut landscapes (23–256 km2) in south-central Quebec. Surveys were conducted in 20 riparian strips (RS), 20 upland strips (US), and 15 control sites (CO) at the periphery of clear-cut landscapes. Overall, 392 signs of hare presence were recorded along 50 km of transects. Snowshoe hares were present in one-third of the strips surveyed and were five times less abundant in US and RS than in CO. The species avoided strip edges. Hares were more common in the wider strips (>100 m), in the strips adjacent to residual forest patches (≥25 ha), or in those having a denser shrub canopy, which is often associated with a greater basal area in balsam fir (Abies balsamea (L.) Mill.). To maintain snowshoe hare at moderate densities in large clear-cut landscapes, we suggest leaving uncut forest strips >100 m wide in areas having a good shrub cover with presence of balsam fir.

Growth of canopy red oak near its northern range limit: current trends, potential drivers, and implications for the future

2020 ◽  
Vol 50 (10) ◽  
pp. 975-988
Author(s):  
Rebecca L. Stern ◽  
Paul G. Schaberg ◽  
Shelly A. Rayback ◽  
Paula F. Murakami ◽  
Christopher F. Hansen ◽  
...  
Keyword(s):  
Acid Deposition ◽  
Basal Area ◽  
Growth Potential ◽  
Tree Age ◽  
Red Oak ◽  
Surprising Result ◽  
Range Limit ◽  
Size Groups ◽  
Northern Range Limit ◽  
Summer Temperatures

Red oak (Quercus rubra L.) is projected to expand into the northern hardwood forest over the coming century. We explored the connection between red oak basal area growth and a number of factors (tree age and size, stand dynamics, site elevation, and climate and acid deposition variables) for 213 trees in 11 plots throughout Vermont, USA. Red oak growth generally increased over the course of the chronology (1935–2014) and has been particularly high in recent decades. Growth differed among elevational groups but did not differ between age or size groups. Summer moisture metrics were consistently and positively associated with growth, whereas fall moisture was associated with reduced growth in recent decades. Higher summer temperatures were often negatively associated with growth, though there was evidence that low temperatures in the summer (higher elevations) and fall (lower elevations) constrain growth. Several pollution metrics were associated with reduced growth, a surprising result for a species not known to be sensitive to inputs of acid deposition that have predisposed other species in the region to decline. While red oak growth is currently robust, increases in summer temperatures, reductions in growing season precipitation, or increases in fall precipitation could reduce future growth potential.

scholarly journals SPRUCE BUDWORM DAMAGE TO BALSAM FIR IN IMMATURE STANDS, QUEBEC

1964 ◽  
Vol 40 (3) ◽  
pp. 372-383 ◽  
Author(s):  
R. J. Hatcher
Keyword(s):  
Minor Component ◽  
Basal Area ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Hardwood Forest ◽  
Cover Type ◽  
Area Reduction ◽  
A Minor ◽  
Very High ◽  
Diameter Classes

A study was made of the effect of the 1945-1957 spruce budworm infestation on 1,800 acres of spruce-fir and spruce-fir-hardwood forest logged for pulpwood about 15 years prior to the infestation.The number of fir trees was reduced 64 per cent between 1951 and 1961 in the main cover type representing 69 per cent of the forest; fir was reduced from a major stand component of 45 per cent by volume to a minor component of 11 per cent. The basal area reduction of fir varied directly with the fir basal area at the time of the outbreak. Losses were very high in stands containing over 20 sq. ft. of fir per acre.These young stands did not exhibit the degree of resistance to damage often observed in young stands elsewhere. But in spite of heavy losses through all diameter classes, the amount of spruce and fir regeneration that survived to 1961 is believed adequate to produce a pulpwood crop within 60 years.

AN ANALYSIS OF MEASURES OF DENSITY IN EVEN-AGED BALSAM FIR AND JACK PINE STANDS

1964 ◽  
Vol 40 (4) ◽  
pp. 474-481 ◽  
Author(s):  
P. E. Vezina
Keyword(s):  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Balsam Fir ◽  
Aerial Photographs ◽  
Growing Stock ◽  
The One ◽  
Crown Closure

The concept of stand density in relation to thinning is examined and its development over the years is discussed. Present difficulties of objectively measuring stand density are recognized and probable future trends towards the development of better formulae to express stand density are outlined. Researchers should continue to collect information on interrelationships among stand variables. Certain merits accrue from description of stand density in terms of variables, such as crown closure, that can be measured with some precision from aerial photographs. Conversely, valid estimates of crown closure which are often difficult to obtain by means of devices from the ground, could be predicted from stand density. Three stand variables, used as expressions of stand density, were tested in crown closure simple regressions in even-aged, unmanaged stands of balsam fir (Abies balsamea (L.) Mill.) and jack pine (Pinus banksiana Lamb.). These are: total number of trees, number of trees 4 inches and up, and basal area per acre. The strongest relationship found was the one where crown closure is compared with basal area; it was stronger for jack pine than for balsam fir. This was explained by differences in tolerance among the two species. The significance of these relationships for the stand development, and the feasibility of using height-and diameter-based indices as measures of growing stock in studies of yield are discussed.

Monitoring of Inorganic Nitrogen Levels in the Surface and Ground Water of the Red River Delta, Northern Vietnam

2004 ◽  
Vol 35 (11-12) ◽  
pp. 1645-1662 ◽  
Author(s):  
Kiyoshi Kurosawa ◽  
Do Nguyen Hai ◽  
Nguyen Huu Thanh ◽  
Ho Thi Lam Tra ◽  
Nguyen Tat Canh ◽  
...  
Keyword(s):  
Ground Water ◽  
Inorganic Nitrogen ◽  
River Delta ◽  
Red River ◽  
Red River Delta ◽  
Northern Vietnam ◽  
Nitrogen Levels

Temporal and Spatial Variations of Inorganic Nitrogen Levels in Surface and Groundwater Around Hanoi, Vietnam

2006 ◽  
Vol 37 (3-4) ◽  
pp. 403-415 ◽  
Author(s):  
Kiyoshi Kurosawa ◽  
Do Nguyen Hai ◽  
Nguyen Huu Thanh ◽  
Ho Thi Lam Tra ◽  
Tran Thi Le Ha ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Spatial Variations ◽  
Temporal And Spatial Variations ◽  
Nitrogen Levels ◽  
Temporal And Spatial ◽  
Surface And Groundwater
Sign in / Sign up

Export Citation Format

Share Document